* {
  box-sizing: border-box;
}

html, body {
  width: 100%;
  height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  background: #222;
  font-family: monospace;
}

h1 {
  margin-top: 0;
}

button {
  font-family: monospace;
  border: 2px solid tomato;
  background: transparent;
  width: 250px;
  font-size: 1.2em;
  padding: 10px 0;
  border-radius: 5px;
  display: block;
  cursor: pointer;
  margin: 1em auto;
}

article {
  width: 80%;
  margin: auto;
  font-size: 2em;
  top: 50%;
  position: relative;
  transform: translateY(-50%);
}